Arm supporting exoskeleton with a variable force generator

ABSTRACT

Described herein is an arm supporting exoskeleton, comprising an arm link mechanism. The arm link mechanism comprises a proximal link, a distal link, an arm coupler, and a variable force generator. The distal link is rotatable relative to the proximal link. The arm coupler is adapted to couple an upper arm of a person to the distal link. The variable force generator comprises a first spring and a second spring, configured to create a torque between the proximal link and the distal link. In the first force mode, the variable force generator exhibits a first stiffness rate defined by the first spring that supports the upper arm of the person against gravity forces and. In the second force mode, the variable force generator exhibits a second stiffness rate defined by the first spring and the second spring that supports the upper arm of the person against the gravity forces.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/997,742, filed on 2020 Aug. 19, which is a continuation of U.S.patent application Ser. No. 16/834,647, filed on 2020 Mar. 30, andissued as U.S. Pat. No. 10,786,896 on 2020 Sep. 29, which is acontinuation of U.S. patent application Ser. No. 16/455,899, filed on2019 Jun. 28, and issued as U.S. Pat. No. 10,639,785 on 2020 May 5,which is a continuation of U.S. patent application Ser. No. 16/242,875,filed on 2019 Jan. 8, and issued as U.S. Pat. No. 10,391,627 on 2019Aug. 27, which claims the benefit under 35 U.S.C. § 119(e) of U.S.Provisional Patent Application No. 62/614,841, filed on 2018 Jan. 8.

U.S. patent application Ser. No. 16/242,875 is also acontinuation-in-part (CIP) application, claiming priority to U.S. patentapplication Ser. No. 16/157,417, filed on 2018 Oct. 11, and issued asU.S. Pat. No. 10,369,690 on 2019 Aug. 6, which is a continuation of U.S.application Ser. No. 15/848,487, filed on 2017 Dec. 20, and issued asU.S. Pat. No. 10,124,485 on 2018 Nov. 13. U.S. application Ser. No.15/848,487 is a continuation of U.S. application Ser. No. 15/158,113,filed on 2016 May 18, and issued as U.S. Pat. No. 9,889,554 on 2018 Feb.13. U.S. application Ser. No. 15/158,113 claims the benefit under 35U.S.C. § 119(e) of U.S. Provisional Patent Application 62/162,871, filedon 2015 May 18. All of the above-referenced applications areincorporated herein by reference in their entirety for all purposes.

TECHNICAL FIELD

The present disclosure pertains to the art of support devices for thehuman arm and, more particularly, to an arm support device configured toreduce the moment on a person's shoulder during arm elevation. Thepresent disclosure is further directed to a variable force generatorapplied to an arm supporting exoskeleton capable of being selectivelytransitioned between at least two stiffness rates. Depending on theconfiguration, these stiffness rates may correspond to high and lowstiffness or an on and off mode, wherein on provides a noticeablestiffness, and off provides a substantially small stiffness that justcompensates for the mass and friction of the device.

BACKGROUND

Conventional passive lift devices, mounted to the torso of a person andconfigured to support the weight of the arm, are not able toautomatically cut or substantially reduce assistance when the personintends to rest his/her upper arm at his/her side, or pick a tool fromhis/her tool belt. Such devices do not provide a sustained range ofposition where support torque automatically reduces to zero. Except fora few position points, these devices continuously apply lifting forcesto a person's upper arm, potentially inhibiting motion and creatingdiscomfort during non-working postures when assist is not desired.

SUMMARY

Methods and devices describes herein provide the person a supportingtorque to raise his/her upper arm thereby reducing the human shoulderforces and torques required to raise the upper arm. However, when theperson intends to rest his/her upper arm at his/her sides or pick a toolfrom his/her tool belt, the device here automatically reduces thelifting force to zero (or substantially small value) allowing the wearerto move her/his upper arm freely. During non-working postures, zero (orsubstantially small) torque is desired to allow free motion of person'supper arm or to allow person's upper arm to rest without the impedanceof an applied torque from the assist device. This creates a greateroverall comfort for person during non-working postures.

In embodiments, an arm supporting exoskeleton configured to be coupledto a person comprises: a shoulder base configured to be coupled to atrunk of the person; and an arm link mechanism configured to be coupledto the shoulder base. The arm link mechanism comprises: a proximal linkand a distal link configured to rotate relative to each other about arotating joint and along a first rotational axis substantiallyorthogonal to a gravity line when the person is standing upright; atleast one arm-coupler adapted to couple an upper arm of the person tothe distal link; a tensile force generator coupled to the proximal linkat a first end of the tensile force generator and coupled to the distallink at a second end of the tensile force generator, the tensile forcegenerator providing a torque to flex the distal link relative to theproximal link; and a protrusion located substantially at the rotatingjoint. When the distal link extends pasta toggle angle, the protrusionconstrains the tensile force generator, and the torque provided by thetensile force generator remains substantially small, and when theprotrusion does not constrain the tensile force generator, the torquehas the tendency to flex the distal link relative to the proximal link,thereby reducing human shoulder forces and torques required to raise theupper arm of the person.

In embodiments, an arm supporting exoskeleton configured to be coupledto a person comprises: a shoulder base configured to be coupled to atrunk of the person; and an arm link mechanism configured to be coupledto the shoulder base. The arm link mechanism comprises: a proximal linkand a distal link configured to rotate relative to each other about arotating joint and along a first rotational axis substantiallyorthogonal to a gravity line when the person is standing upright; atleast one arm-coupler adapted to couple an upper arm of the person tothe distal link; and a tensile force generator coupled to the proximallink at a first end of the tensile force generator and coupled to thedistal link at a second end of the tensile force generator, the tensileforce generator providing a torque to flex the distal link relative tothe proximal link. When the arm support exoskeleton is coupled to theperson and an angle between the proximal link and the distal link issmaller than a toggle angle, the torque has the tendency to flex thedistal link relative to the proximal link, thereby reducing humanshoulder forces and torques required to raise the upper arm of theperson and imposing reaction forces and torques on the shoulder base.When the angle between the proximal link and the distal link is largerthan the toggle angle, the tensile force generator provides asubstantially small torque between the proximal link and the distallink, allowing the person to move the upper arm of the person freely.

In one embodiment, a variable force generator is used at the tensileforce generator, or torque generator, attached to an arm link mechanismof an arm supporting exoskeleton to create a torque about a rotatingjoint that allows for elevation of a person's arm. When a base of thearm supporting exoskeleton is attached to a person's torso and an arm ofthe arm supporting exoskeleton is attached to a person's arm, the torquecreated from the variable force generator serves to flex the person'sarm and support it against the force of gravity. The variable forcegenerator is configured to create at least two different stiffnessrates. When the variable force generator creates a first stiffness, afirst torque is applied to the person's arm that is substantially smalland allows the person to flex and extend the upper arm with minimalinhibition from the created first torque throughout the range of motionof person's arm. When the variable force generator creates a secondstiffness, a second torque is applied to the person's arm that issubstantially higher than the first torque mode and serves to supportthe person's arm against the forces of gravity.

It can be appreciated that while described as a part of an armsupporting exoskeleton, the variable force generator can be applied tocreate forces and torques across a multitude of joints and in manydifferent applications.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a rear perspective view of an assist device, with a person'sarm outstretched.

FIG. 2 is a close-up view of an arm link mechanism.

FIG. 3 is a close up rear perspective view of an arm link mechanism.

FIG. 4 is a side view of an assist device, wherein a first angle is lessthan a toggle angle.

FIG. 5 is a side view of an assist device, wherein a first angle isgreater than a toggle angle.

FIG. 6 is a front perspective view of an arm support exoskeleton,including two arm link mechanisms.

FIG. 7 is a front view of a person showing frontal plane and widthdimensions.

FIG. 8 is a back view of a person showing length dimensions.

FIG. 9 is a side view of a person showing width dimensions.

FIG. 10 is a rear view of a load bearing structure including a backframe and a hip loading belt.

FIG. 11 is a rear view of a back frame including an upper frame and alower frame.

FIG. 12 is a rear view of a back frame including a spine frame.

FIG. 13 is a rear view of an upper frame and a lower frame includingwidth and depth adjusters.

FIG. 14 is a front perspective view of a coupling mechanism including abelt, a chest strap, and an anchor strap.

FIG. 15 is rear view of a coupling mechanism including a belt, a cheststrap, and an anchor strap.

FIG. 16 is a back perspective view of a coupling mechanism including abelt, a chest strap, and an anchor strap.

FIG. 17 is a front perspective view of a coupling mechanism including abelt, a shoulder strap, and a sternum strap.

FIG. 18 is a rear view of a coupling mechanism including a belt, ashoulder strap, and a sternum strap.

FIG. 19 is a back perspective view of a coupling mechanism comprising abelt, a shoulder strap, and a sternum strap.

FIG. 20 is a front perspective view of a coupling mechanism including abelt and a vest.

FIG. 21 is a rear view of a coupling mechanism including a belt and avest.

FIG. 22 is a back perspective view of a coupling mechanism including abelt and a vest.

FIG. 23 is a front perspective view of a coupling mechanism including avest connected to a safety harness.

FIG. 24 is a rear perspective view of a coupling mechanism including avest connected to a safety harness.

FIG. 25 is a rear perspective view of a coupling mechanism including abelt connected to a safety harness.

FIG. 26 is a rear perspective close up view of an assist device showinga first rotational axis aligning with a person's glenohumeral joint.

FIG. 27 is a rear view of an assist device showing a first rotationalaxis aligning with a person's glenohumeral joint.

FIG. 28 is a perspective view of an arm link mechanism including asecond rotational axis.

FIG. 29 is a rear close up view of the second rotational axis of FIG. 28aligning with a person's glenohumeral joint.

FIG. 30 is a perspective view of shoulder bracket connecting a shoulderbase to arm link mechanism.

FIG. 31 is a perspective view of a shoulder bracket showing an arm linkmechanism removed from a shoulder base.

FIG. 32 is a perspective view of a shoulder bracket allowing shoulderwidth adjustment of an arm supporting exoskeleton.

FIG. 33 is a perspective view of a shoulder bracket, showing a scapularrotation axis.

FIG. 34 is a front perspective view of a person with an arm supportexoskeleton in a stowed position.

FIG. 35 is a perspective view of an arm supporting exoskeleton in aworking position.

FIG. 36 is a perspective view of an arm supporting exoskeleton in astowed position.

FIG. 37 is a perspective view of an arm link mechanism containing an armcoupler.

FIG. 38 is a perspective view of an arm link mechanism wherein an armcoupler contains an arm rotation joint.

FIG. 39 is a perspective view of an arm link mechanism wherein an armcoupler contains a translation joint.

FIG. 40 is a section view of an arm coupler containing a translationjoint.

FIG. 41 is a front view of an arm coupler containing an internalexternal rotation joint.

FIG. 42 is a side section view of a torque generator with an extensionspring.

FIG. 43 is a schematic of a torque generator.

FIG. 44 is an alternative side section view of a torque generator withan extension spring.

FIG. 45 is a side section view of a torque generator with a compressionspring.

FIG. 46 is an alternative side section view of torque generator withcompression spring.

FIG. 47 is a side section view of a torque generator with an upperbracket in a raised position.

FIG. 48 is a side section view of a torque generator with an upperbracket in a lowered position.

FIG. 49 is a plot of a torque generator torque profile for two positionsof an upper bracket.

FIG. 50 is a side section view of a torque generator with a lowerbracket in an extended position.

FIG. 51 is a side section view of a torque generator with a lowerbracket in a retracted position.

FIG. 52 is a plot of a torque generator torque profile for two positionsof a lower bracket.

FIG. 53 is a side section view of torque generator with protrusion wherefirst angle is larger than a toggle angle.

FIG. 54 is a close up side section view of a torque generator includinga protrusion comprising a joint pin.

FIG. 55 is a close up side section view a torque generator including aprotrusion that is part of a proximal link.

FIG. 56 is a plot of a torque generator torque profile withoutprotrusion.

FIG. 57 is a plot of a torque generator torque profile with protrusion.

FIG. 58 is a side section view of a torque generator including an offsetadjustment joint.

FIG. 59 is a side section view of a torque generator showing an offsetposition increased.

FIG. 60 is an exploded perspective view of arm link mechanism showingoffset adjustment joint.

FIG. 61 is a plot of a torque generator torque profile for two values ofan offset adjustment angle.

FIG. 62 is an example of a desired torque generator support torqueprofile compared to an arm weight torque profile.

FIG. 63 is an alternative example of a desired torque generator supporttorque profile compared to an arm weight torque profile.

FIG. 64 is an alternative example of a desired torque generator supporttorque profile compared to an arm weight torque profile.

FIG. 65 is a front perspective view of a back frame coupled to a lowerextremity exoskeleton.

FIG. 66 is a front perspective view of a back frame coupled to a trunkexoskeleton.

FIG. 67 is a schematic of a variable force generator.

FIG. 68 is an axial section view of a variable force generator.

FIG. 69 is an axial section view of a variable force generator creatinga first tensile force.

FIG. 70 is an axial section view of a variable force generator creatinga second tensile force.

FIG. 71 is an axial section view of a variable force generator creatinga first compressive force.

FIG. 72 is a radial section view of a variable force generator withconstraining mechanism in first position.

FIG. 73 is a radial section view of a variable force generator withconstraining mechanism in second position

FIG. 74 is a detailed section view of a variable force generator at atransition position with constraining mechanism in a second position.

FIG. 75 is a detailed section view of a variable force generator at atransition position with constraining mechanism in a first position.

FIG. 76 is a detailed section view of a variable force generatorcreating a second tensile force.

FIG. 77 is a detailed section view of a variable force generatorcreating a first tensile force.

FIG. 78 is an embodiment of a retaining ring type constrainingmechanism.

FIG. 79 is an embodiment of a rotating type constraining mechanism.

FIG. 80 is an alternate embodiment of a rotating type constrainingmechanism.

FIG. 81 is an embodiment of a hook type constraining mechanism.

FIG. 82 is an embodiment of an integrated constraining mechanism.

FIG. 83 is an embodiment of a screw type constraining mechanism.

FIG. 84 is an embodiment of a clamp type constraining mechanism.

FIG. 85 is a close up section view of an embodiment of a constrainingmechanism and switch.

FIG. 86 is a close up section view of an alternate embodiment of aconstraining mechanism and switch.

FIG. 87 is a close up section view of an embodiment of a constrainingmechanism and wedge element.

FIG. 88 is a close up section view of an alternate embodiment of aconstraining mechanism and wedge element.

FIG. 89 is a section view of a variable force generator configured tocreate a first torque.

FIG. 90 is a section view of a variable force generator configured tocreate a second torque.

FIG. 91 is a section view of an alternate embodiment of a variable forcegenerator configured to create a second torque.

FIG. 92 is a section view of variable force generator configured tocreate a torque at a first transition angle

FIG. 93 is a section view of a variable force generator configured tocreate a torque at a second transition angle.

FIG. 94 is a perspective view of a variable force generator as part ofan arm supporting exoskeleton.

FIG. 95 is a schematic of a first alternate embodiment of a variableforce generator with three stiffness settings.

FIG. 96 is a section view of a first alternate embodiment of a variableforce generator with three stiffness settings

FIG. 97 is a schematic of a second alternate embodiment of a variableforce generator with three stiffness settings.

FIG. 98 is a section view of a second alternate embodiment of a variableforce generator with three stiffness settings.

FIG. 99 is a schematic of a third alternate embodiment of a variableforce generator with three stiffness settings.

FIG. 100 is a section view of a third alternate embodiment of a variableforce generator with three stiffness settings.

FIG. 101 is a schematic of an alternate embodiment of a variable forcegenerator with extension springs.

FIG. 102 is a section view of an alternate embodiment of a variableforce generator with extension springs generating a second force.

FIG. 103 is a section view of an alternate embodiment of a variableforce generator with extension springs generating a first force.

FIG. 104 is a section view of an alternate embodiment of a variableforce generator with extension springs with a hook type constrainingmechanism.

FIG. 105 is a section view of an alternate embodiment of a variableforce generator with extension springs with a rotating type constrainingmechanism.

FIG. 106 is a schematic of a first alternate embodiment of a variableforce generator with series springs.

FIG. 107 is a section view of a first alternate embodiment of a variableforce generator with series.

FIG. 108 is a schematic of a second alternate embodiment of a variableforce generator with series springs.

FIG. 109 is a schematic of a third alternate embodiment of a variableforce generator with series springs.

FIG. 110 is a schematic of a fourth alternate embodiment of a variableforce generator with series springs.

DETAILED DESCRIPTION

FIG. 1 depicts an embodiment of arm support exoskeleton 100, which maybe also referred to as an assist device. Arm support exoskeleton 100comprises shoulder base 102, which is configured to be coupled to trunk202 of person 200. In some embodiments, shoulder base 102 issubstantially located behind person 200, which may be also referred toas a user. Arm support exoskeleton 100 additionally comprises at leastone arm link mechanism 104 that is coupled to shoulder base 102. Armlink mechanism 104 comprises at least proximal link 150 and distal link152 capable of rotation relative to each other along first rotationalaxis 154. In some embodiments, first rotational axis 154 is orthogonalto the gravity line 208 when person 200 in standing upright. The term“gravity line” should be understood to mean the direction in whichgravity acts. First joint 151 represents a hinge, where distal link 152rotates relative to proximal link 150. Arm support exoskeleton 100additionally comprises at least one arm coupler 106 that couples upperarm 204 (of person 200) to distal link 152 of arm link mechanism 104.Arm coupler 106 is depicted in FIG. 2 . Arm support exoskeleton 100additionally comprises at least one torque generator 108 configured tocreate torque 280 between proximal link 150 and distal link 152. A closeup view of arm link mechanism 104 is depicted in FIG. 3 . Torque 280 inFIG. 1 and FIG. 3 shows the torque imposed on distal link 152 fromproximal link 150. As shown in FIG. 4 , first angle 193 represents anangle between proximal link 150 and distal link 152. When first angle193 is smaller than toggle angle 195, as depicted in FIG. 4 , torquegenerator 108 generates torque 280 that has the tendency to flex distallink 152 relative to proximal link 150. The term “toggle angle” shouldbe understood to mean the angle between a first position (e.g., arm israised) in which proximal link 150 and distal link 152 are collinear,and a second position (e.g., arm is lowered) in which the proximal link150 and distal link 152 become collinear. The term “flex” should beunderstood to mean a movement of distal link 152 resulting in thedecrease of first angle 193, while the term “extend” as used hereinshould be understood to mean a movement of distal link 152 resulting inthe increase of first angle 193. The torque 280 produces supportingforce 212 (shown in FIG. 2 and FIG. 4 ) onto upper arm 204 by armcoupler 106. This reduces the human shoulder forces and torques requiredto raise upper arm 204 and imposes set reaction force 214 and reactiontorque 215 on shoulder base 102.

When angle 193 is larger than toggle angle 195 as depicted in FIG. 5 ,torque generator 108 provides a substantially small torque betweenproximal link 150 and distal link 152. The term “substantially smalltorque” should be understood to mean a torque value which does not causesubstantial inhibition or discomfort of upper arm 204. This allowsperson 200 to move her/his upper arm 204 freely. In the Example shown inFIG. 5 , when upper arm 204 (of person 200) is lowered, a position ofdistal link 152 moves past a position of collinear alignment withproximal link 150, and torque generator 108 provides substantially smalltorque between proximal link 150 and distal link 152 such that theperson can easily maneuver their upper arm 204 in this lowered position.

FIG. 6 depicts another embodiment of arm support exoskeleton 100including two arm link mechanisms 104 connected to shoulder base 102,each including at least one torque generator 108 and at least one armcoupler 106. In some embodiments, distal link 152 moves in such a mannerthat it remains substantially parallel with upper arm 204.

In some embodiments, as depicted in FIG. 6 , shoulder base 102 of armsupporting exoskeleton 100 comprises load bearing structure 112 coupledto arm link mechanism 104 and coupling mechanism 114 that attachesshoulder base 102 to trunk 202 of person 200. Load bearing structure 112supports reaction forces 214 and reaction torques 215 from arm linkmechanisms 104. In some embodiments, as depicted in FIG. 10 through FIG.13 , reaction forces 214 and reaction torques 215 transfer to person200. In some embodiments, as depicted in FIG. 65 , reaction forces 214and reaction torques 215 transfer to a support surface (e.g., ground310). Various embodiments of load bearing structure 112 and couplingmechanism 114 are described below.

FIGS. 7, 8, and 9 are presented here to describe various dimensions usedherein in the description of load bearing structure 112. FIG. 7 depictsa front view of person 200 including hip width 234, shoulder width 236,and frontal plane 250 of person 200. FIG. 8 depicts a back view ofperson 200, including torso height 232 and upper arm length 242. FIG. 9depicts a side view of person 200 including hip depth 238 and shoulderdepth 240.

FIG. 10 through FIG. 13 depict various embodiments of load bearingstructures 112. As depicted in FIG. 10 , in embodiments, load bearingstructure 112 comprises back frame 130 supporting reaction forces 214and torques 215 from arm link mechanisms 104 (not shown) and hip loadingbelt 131. Hip loading belt 131 transfers at least a portion of thereaction forces 214 and reaction torques 215 to hips 220 of person 200(shown in FIG. 14 ), resulting in hip reaction force 221. Back frame 130may also transfer at least a portion of the reaction forces 214 toshoulders 224 of person 200 (depicted in FIG. 14 ), as illustrated byshoulder reaction forces 225. Back frame 130 can be custom made, orincrementally sized, to accommodate torso height 232, hip width 234,shoulder width 236, hip depth 238, shoulder depth 240, or anycombination thereof. In some embodiments, hip loading belt 131 and backframe 130 are constructed as one item.

FIG. 11 depicts a further embodiment of load bearing structure 112wherein back frame 130 comprises upper frame 136 coupled to arm linkmechanisms 104 (not shown) and lower frame 138 translationally coupledto upper frame 136 to provide desirable torso height adjustment 233 fortorso height 232. Lower frame 138 is coupled to, or part of, hip loadingbelt 131. Reaction forces 214 from arm link mechanisms 104 are supportedby upper frame 136, at least a portion of which are transferred to hips220 by hip loading belt 131 via lower frame 138, resulting in hipreaction force 221. Upper Frame 136 may also transfer at least a portionof the reaction forces 214 to shoulders 224, as depicted by shoulderreaction forces 225. Upper frame 136 can be custom made, orincrementally sized, to accommodate shoulder width 236 and shoulderdepth 240. Lower frame 138 can be custom made, or incrementally sized,to accommodate hip width 234 and hip depth 238.

FIG. 12 depicts a further embodiment of load bearing structure 112wherein back frame 130 further comprises spine frame 134 connectingupper frame 136 to lower frame 138. Spine frame 134 is rotatably coupledto lower frame 138 on its lower end allowing for rotation of spine frame134 relative to lower frame 138 in frontal plane 250 (FIG. 7 ) of person200. Mediolateral flexion motion 260 shows the direction of movementbetween spine frame 134 and lower frame 138. Spine frame 134 isrotatably coupled to upper frame 136 along spine frame axis 135. Spinaltwisting motion 262 shows the direction of movement between spine frame134 and upper frame 136. Upper frame 136 may also translate relative tospine frame 134 along spine frame axis 135 to provide torso heightadjustment 233 for torso height 232 of person 200. Degrees of freedom ofspinal twisting motion 262 between upper frame 136 and spine frame 134and mediolateral flexion motion 260 between lower frame 138 and spineframe 134 allow upper frame 136 to substantially move in unison withchest 222 of person 200 (depicted in FIG. 14 ), and lower frame 138 tosubstantially move in unison with hips 220 of person 200.

FIG. 13 depicts another embodiment of load bearing structure 112 whereinlower frame 138 further comprises lower middle bar 144 and two lowercorner bars 140 wherein each lower corner bar 140 can be coupled tolower middle bar 144 at various locations on the lower middle bar 144 toprovide desirable hip width adjustment 235 to accommodate hip width 234of person 200. Lower frame 138 may further comprise two lower sidebrackets 149 wherein each lower side bracket 149 can be coupled to lowerframe 138 at various locations on lower frame 138 to provide desirablehip depth adjustment 239 to accommodate hip depth 238 of person 200.Upper frame 136 further comprises upper middle bar 142 and two uppercorner bars 146 wherein each upper corner bar 146 can be coupled toupper middle bar 142 at various locations on upper middle bar 142 toprovide desirable shoulder width adjustment 237 to accommodate shoulderwidth 236 of person 200. Upper frame 136 may also comprise two upperside brackets 148 wherein each upper side bracket 148 can be coupled toupper frame 136 at various locations on upper frame 136 to providedesirable shoulder depth adjustment 241 to accommodate shoulder depth240 of person 200. Upper frame 136 may also comprise hammocks 128spanning curves in upper frame 136 to more evenly distribute respectiveshoulder reaction force 225 (depicted in FIG. 13 ) to shoulders 224 ofperson 200 (depicted in FIG. 14 ). Adjustment of upper side brackets,upper corner bars, lower side brackets, and lower corner bars mayinclude the use of plunger pins, screws, clamps, friction locks, rackand pinions, or any combination thereof.

FIG. 14 through FIG. 22 depict various embodiments where couplingmechanism 114 includes belt 116 that attaches to load bearing structure112 at belt attachment points 115 and at least partially encircles hips220 of person 200. Belt 116 can move in unison with hips 220 of person200. In some embodiments, belt 116 can change length to allow secureattachment to hips 220.

FIGS. 14,15 and 16 depict various embodiments of the shoulder base 102.FIG. 14 shows a front perspective view of shoulder base 102 with person200. FIG. 15 shows a rear view of shoulder base 102 without person 200.FIG. 16 shows a rear perspective view of shoulder base 102 withoutperson 200. In this embodiment, a coupling mechanism 114 includes cheststrap 118. Chest strap 118 at least partially encircles chest 222 ofperson 200. Chest strap 118 is mounted to load bearing structure 112 atmid-dorsal attachment points 117 approximately at the level of chest222. In some embodiments, coupling mechanism 114 includes at least oneanchor strap 119 mounted to load bearing structure 112 at upper ventralattachment points 121 at its first end, and attaches to chest strap 118at its second end. Chest strap 118 and anchor strap 119 move in unisonwith chest 222. In some embodiments, chest strap 118 and anchor strap119 can change length to allow secure attachment to chest 222. In someembodiments, chest strap 118 is rigid to prevent deflection due to thetightening of anchor straps 119.

FIGS. 17,18 and 19 depict various embodiments of the shoulder base 102.FIG. 17 shows a front perspective view of shoulder base 102 with person200. FIG. 18 shows a rear view of shoulder base 102 without person 200.FIG. 19 shows a rear perspective view of shoulder base 102 withoutperson 200. In this embodiment, coupling mechanism 114 includes at leasttwo shoulder straps 120. Two shoulder straps 120 at least partiallyencircle shoulders 224. Each shoulder strap 120 is mounted to loadbearing structure 112 at respective upper ventral attachment points 121on a first end and at lower dorsal attachment points 123 on a secondend. In some embodiments, sternum strap 122 connects to one shoulderstrap 120 at its first end and another shoulder strap 120 at its secondend. Shoulder strap 120 and sternum strap 122 move in unison with chest222. In some embodiments, shoulder strap 120 and sternum strap 122 canchange length to allow secure attachment to chest 222. In someembodiments, shoulder strap 120 is mounted to load bearing structure 112at upper ventral attachment point 121 on its first end and middle dorsalattachment points 117 at its second end.

FIGS. 20, 21 and 22 depict various embodiments of the shoulder base 102.FIG. 20 shows a front perspective view of shoulder base 102 with person200. FIG. 21 shows a rear view of shoulder base 102 without person 200.FIG. 22 shows a rear perspective view of shoulder base 102 withoutperson 200. In this embodiment, coupling mechanism 114 includes vest 124that securely attaches to chest 222. Vest 124 can move in unison withchest 222. In some embodiments, vest 124 is connected to shoulder base102 by a plurality of vest attachment points 125. In some embodiments,vest attachment points 125 attach to chest straps 118, anchor straps119, shoulder straps 120, sternum straps 122, or any combinationthereof.

FIG. 23 through FIG. 25 depict embodiments of shoulder base 102 whereincoupling mechanism 114 can be coupled to safety harness 126 worn byperson 200 by at least one safety harness attachment point 127 withoutmodification of safety harness 126. FIG. 23 and FIG. 24 depict anembodiment wherein vest 124 contains at least one safety harnessattachment point 127. Safety harness attachment points 127 allow vest124 to attach to safety harness 126 without modification of safetyharness 126. Safety harness attachment points 127 may be located on thefront, shoulder, or back of vest 124. FIG. 23 shows a front perspectiveview of safety harness attachment points 127 on the front and shouldersof vest 124. FIG. 24 depicts a close up back perspective view of theembodiment (without load bearing structure 112), including safetyharness attachment points 127 on a back and shoulders of vest 124.Safety harness attachment points 127 may be formed by VELCRO® loops,buttoned flaps, straps, buckles, clips, clamps, or any combinationthereof. FIG. 25 depicts an embodiment wherein belt 116 contains atleast one safety harness attachment point 127. Safety harness attachmentpoint 127 allows safety harness 126 to be attached to belt 116 withoutmodification of safety harness 126. In some embodiments, safety harnessattachment points 127 are located on the sides of belt 116. Safetyharness attachment points 127 may be formed by VELCRO® loops, buttonedflaps, straps, buckles, clips, clamps, or any combination thereof.

FIG. 26 depicts the close up view of arm link mechanism 104. In thisembodiment, first rotational axis 154 of first joint 151 approximatelypasses through glenohumeral joint 218 of person 200. FIG. 27 depicts aback view of this embodiment wherein arm support exoskeleton 100contains two arm link mechanisms 104.

FIG. 28 and FIG. 29 depict another embodiment of arm supportingexoskeleton 100 wherein arm link mechanism 104 comprises at least onehorizontal rotation joint 156. Horizontal rotation joint 156 allowsproximal link 150 to rotate relative to shoulder base 102 about secondrotational axis 155. Second rotational axis 155 is substantiallyorthogonal to first rotational axis 154. FIG. 29 shows a rear view ofthe arm link mechanism 104, wherein the second rotational axis 155 isshown to substantially pass through glenohumeral joint 218 of person200.

FIG. 30 and FIG. 31 depict an embodiment of arm support exoskeleton 100that comprises at least one shoulder bracket 153 coupled to shoulderbase 102. Shoulder bracket 153 facilitates a quick connect anddisconnect coupling between arm link mechanism 104 and shoulder base102. FIG. 30 depicts shoulder bracket 153 coupling arm link mechanism104 to shoulder base 102. FIG. 31 shows shoulder bracket 153 allowingarm link mechanism 104 to be removed from shoulder base 102.

FIG. 32 depicts another embodiment of arm support exoskeleton 100 thatcomprises at least one shoulder bracket 153 coupled to shoulder base102. Shoulder bracket 153 can couple shoulder base 102 to arm linkmechanism 104 in multiple positions to provide desirable shoulder widthadjustment 237 to accommodate shoulder width 236 of person 200,referenced in FIG. 7 . In another embodiment not depicted, shoulderbracket 153 can couple to arm link mechanism 104 in multiple positionsto provide desirable shoulder depth adjustment 241 to accommodateshoulder depth 240 of person 200.

FIG. 33 depicts another embodiment of arm supporting exoskeleton 100wherein shoulder base 102 comprises at least one shoulder bracket 153.Shoulder bracket 153 is rotatably coupled to arm link mechanism 104along scapular rotation axis 171, wherein the scapular rotation axis 171is substantially orthogonal to gravity line 208 when person 200 (notshown) is standing upright.

FIG. 34 through FIG. 36 depict another embodiment of arm supportexoskeleton 100, wherein shoulder base 102 is coupled to a shoulderbracket 153. Shoulder bracket 153 couples to arm link mechanism 104.Shoulder bracket 153 contains stow joint 158 that allows shoulderbracket 153 to rotate relative to shoulder base 102 (stow joint 158 notdepicted in FIG. 34 ). When shoulder bracket 153 rotates about stowjoint 158, it may position arm link mechanism 104 substantially behindperson 200. Shoulder bracket 153 can be held stationary about stow joint158 to keep arm link mechanism 104 in the desired orientation. FIG. 34shows person 200 wearing arm supporting exoskeleton 100 wherein arm linkmechanism 104 is in a stowed position that is substantially out ofworkspace 230 of person. The term “workspace of person” or “person'sworkspace” should be understood to mean the range of motion of upper arm204 of person 200 that may be utilized during common workplace tasks.FIG. 35 shows perspective view of shoulder bracket 153 in a workingposition. In the working position arm link mechanism 104 is positionedto support upper arm 204 (not shown). FIG. 36 shows a perspective ofshoulder bracket 153 in a stowed position wherein arm link mechanism 104is positioned substantially behind person 200 (not shown). In a stowedposition, distal link 152 remains fully flexed relative to proximal link150 due to torque generator 108 acting about first rotational axis 154.This serves to further secure arm link mechanism 104 out of workspace230. It should be understood that other joints between arm linkmechanism 104 and shoulder base 102 may be utilized to further securearm link mechanism 104 out of workspace 230.

FIG. 37 through FIG. 41 depict embodiments of arm supporting exoskeleton100 wherein arm coupler 106 further comprises a load bearing coupler 160coupled to distal link 152 capable of imposing supporting force 212,directed upward, on upper arm 204 (shown in FIG. 1 ). In someembodiments, load bearing coupler 160 comprises distal link attachment167 that attaches arm coupler 106 to distal link 152 and at least onearm cuff 168 that at least partially encircles upper arm 204 (shown inFIG. 1 ).

FIG. 37 depicts an embodiment of arm support exoskeleton 100 wherein armcoupler 106 further comprises an arm coupling mechanism 162. Armcoupling mechanism 162 is capable of coupling arm coupler 106 to upperarm 204 (shown in FIG. 2 ). Arm coupling mechanism 162 may comprise anelement or combination of elements selected from a group consisting ofrigid, semi-rigid, or compliant materials preventing separation of upperarm 204 (shown in FIG. 1 ) from arm coupler 106.

FIG. 38 depicts an embodiment of arm coupler 106 wherein load bearingcoupler 160 contains an arm rotation joint 164. Arm rotation joint 164allows arm cuff 168 to rotate with respect to distal link 152 along armcuff rotation axis 165 substantially parallel to first rotational axis154. Arm rotation joint 164 allows arm cuff 168 to provide maximumcontact with upper arm 204 (shown in FIG. 1 ) or compensate for movementdiscrepancies between distal link 152 and upper arm 204 of person 200.

FIG. 39 depicts an embodiment of arm coupler 106 wherein arm coupler 106locations can be adjusted with respect to distal link 152. In someembodiments, load bearing coupler 160 can translate with respect todistal link 152 at translation joint 166 to allow for arm lengthadjustment 243 of arm link mechanism 104 to fit length 242 of upper arm204 of person 200 (referenced in FIG. 7 ), or to compensate for anymovement discrepancies between distal link 152 and s upper arm 204 ofperson 200 (depicted in FIG. 1 ). FIG. 40 depicts another embodiment oftranslation joint 166 wherein distal link 152 contains a t-slot matingwith load bearing coupler 160. Load bearing 160 contains locking pin 169that fixes the position of load bearing coupler 160 relative to distallink 152.

FIG. 41 depicts an embodiment of arm coupler 106 wherein load bearingcoupler 160 allows for internal and external rotation of upper arm 204(shown in FIG. 1 ) with internal/external rotation joint 172.Internal/external rotation joint 172 is located between distal linkattachment 167 and arm cuff 168. Internal/external rotation joint 172rotates about internal external rotation axis 173. In another embodimentnot depicted, sliding contact with upper arm 204 resting in arm cuff 168allows for rotation about internal external rotation axis 173.

FIG. 42 through FIG. 46 depict various embodiments of arm supportingexoskeleton 100 wherein torque generator 108 comprises tensile forcegenerator 178. Tensile force generator 178, as shown in FIG. 42 , iscoupled to proximal link 150 from its first tensile end 176 and distallink 152 from its second tensile end 177. The tensile force in tensileforce generator 178 provides torque 280 to flex distal link 152 relativeto proximal link 150 about first rotational joint 151. In someembodiments of torque generator 108, tensile force generator 178comprises coil spring element 180. In some embodiments of torquegenerator 108, tensile force generator 178 comprises line elementcoupling coil spring element 180 to proximal link 150. Line element 182comprises an element or combination of elements selected from a groupconsisting of wire rope, rope, cable, twine, strap, chain, or anycombination thereof. In some embodiments of torque generator 108, lineelement 182 at least partially encircles pulley 183 coupled to distallink 152 before line element 182 is coupled to proximal link 150. Insome embodiments pulley 183 does not rotate relative to distal link 152.In some embodiments, pulley 183 is a curved surface incorporated intodistal link 152. FIG. 42 depicts an embodiment of torque generator 108where coil spring element 180 is an extension spring. Coil springelement 180 is coupled to line element 182 at junction 179 and coupledto distal link 152 at second tensile end 177.

FIG. 43 shows an approximate schematic of torque generator 108. Tensileforce generator 178 is coupled to proximal link 150 at first distance272. Tensile force generator 178 acts about distal link at seconddistance 270. Tensile force generator effective length 276 is thedistance between first distance 272 along proximal link 150 and seconddistance 270 along distal link 152. Tensile force generator originallength is the tensile force generator effective length 276 correspondingto a zero value of first angle 193. Tensile force is a function ofspring constant, spring preload, tensile force generator originallength, and tensile force generator effective length 276 at a givenvalue of first angle 193. Torque 280 causes distal link to flex relativeto shoulder base 102.

FIG. 44 through FIG. 46 depicts various embodiments of torque generator108 wherein tensile force generator 178 comprises coil spring element180 and line element 182. Line element 182 at least partially encirclespulley 183 coupled to distal link 152. FIG. 44 depicts an embodiment oftorque generator 108 where coil spring element 180 is an extensionspring with a different orientation than shown in FIG. 42 . Coil springelement 180 is coupled to line element 182 at junction 179 and coupledto distal link 152 at second tensile end 177. In some embodiments, lineelement 182 at least partially wraps around pulley 183 attached todistal link 152 before attaching to proximal link 150. FIG. 45 depictsan embodiment of torque generator 108 where coil spring element 180 is acompression spring. Coil spring element 180 is coupled to line element182 at junction 179 and coupled to distal link 152 at second tensile end177. In some embodiments, line element 182 at least partially wrapsaround pulley 183 attached to distal link 152 before attaching toproximal link 150. FIG. 46 depicts an embodiment of torque generator 108where coil spring element 180 is a compression spring with a differentorientation than shown in FIG. 45 . Coil spring element 180 is coupledto line element 182 at junction 179 and coupled to distal link 152 atsecond tensile end 177. In some embodiments, line element 182 at leastpartially wraps around pulley 183 attached to distal link 152 beforeattaching to proximal link 150. It is understood that in allembodiments, instead of coil spring element 180, a gas spring, airspring, elastomer, or any combination that exhibits similar behavior canbe utilized.

FIG. 47 and FIG. 48 depict an embodiment of torque generator 108 whereinproximal link 150 comprises an upper bracket 188 coupled to tensileforce generator 178. The location of upper bracket 188 can be adjustedalong proximal link 150 to adjust torque 280 provided by tensile forcegenerator 178. The location of upper bracket 188 corresponds to firstdistance 272 in the schematic of FIG. 43 . In some embodiments, thelocation of upper bracket 188 is adjusted relative to proximal link 150by upper bracket screw 187 where upper bracket 188 incorporates athreaded feature that mates with upper bracket screw 187. By turningupper bracket screw 187, the location of upper bracket 188 is adjustedalong proximal link 150. In general, the farther upper bracket 188 isfrom first joint 151, the larger the amplitude of torque 280 will be.FIG. 47 depicts upper bracket 188 in an extended position relative tofirst joint 151, resulting in a large first distance 272 (see FIG. 43 ).FIG. 48 depicts upper bracket 188 in a retracted position relative tofirst joint 151, resulting in a small first distance 272 (see FIG. 42 ).FIG. 49 depicts two plots of torque 280 created by torque generator 108as a function of first angle 193 for two positions of upper bracket 188described in FIG. 47 and FIG. 48 . The torque profile of configurationshown in FIG. 47 is represented by torque profile 288. The torqueprofile of configuration shown in FIG. 48 is represented by torqueprofile 287. It can be seen that torque profile 288 has larger amplitudecompared to torque profile 287.

FIG. 50 and FIG. 51 depict an embodiment of torque generator 108 whereindistal link 152 comprises lower bracket 190 coupled to tensile forcegenerator 178. The location of lower bracket 190 can be adjusted alongdistal link 152 to adjust torque 280 provided by tensile force generator178. The location of lower bracket 190 corresponds to preload of tensileforce generator 178. In some embodiments, the location of lower bracket190 is adjusted relative to distal link 152 by lower bracket screw 189where lower bracket 190 incorporates a threaded feature that mates withlower bracket screw 189. By turning lower bracket screw 189, thelocation of lower bracket 190 is adjusted along distal link 152. Ingeneral, the farther lower bracket 190 is from first joint 151, thesmaller the amount of preload will be. FIG. 50 depicts lower bracket 190in a lengthened position relative to first joint 151, resulting in asmall tensile force generator 178 preload. FIG. 51 depicts lower bracket190 in a shortened position relative to first joint 151, resulting in alarge tensile force generator 178 preload. FIG. 52 depicts two plots oftorque 280 created by torque generator 108 as a function of first angle193 for two positions of lower bracket 190 described in FIG. 50 and FIG.51 . The torque profile of configuration shown in FIG. 50 is representedby torque profile 290. The torque profile of configuration shown in FIG.51 is represented by torque profile 289. Shortened lower bracket torqueprofile 289 has a larger amplitude compared to lengthened lower brackettorque profile 290.

FIG. 53 through FIG. 55 depict an important characteristic where thetorque 280 provided by tensile force generator 178 will automaticallyremain substantially small when first angle 193 is greater than or equalto toggle angle 195. That is, when a person moves their arm from a firstposition wherein first angle 193 is not greater than or equal to toggleangle 195, to a second position wherein first angle 193 is greater thanor equal to toggle angle 195, tensile force generator 178 willautomatically shift from a first torque mode wherein a first torque isprovided by tensile force generator 178 (at the first position of thearm), to a second torque mode (at the second position of the arm)wherein a substantially small torque will be provided by tensile forcegenerator 178. Likewise, when a person moves their arm back from thesecond position to the first position, the tensile force generator 178will automatically shift from the second torque mode to the first torquemode.

FIG. 53 shows a configuration where first angle 193 is larger than 180degrees, and arm link mechanism 104 comprises a protrusion 186 locatedsubstantially at first joint 151. When first angle 193 becomes equal toor greater than toggle angle 195, protrusion 186 constrains tensileforce generator 178 (line element 182 of force generator 178 as shown inFIG. 53 ) in a position substantially centered about first joint 151. Byconstraining tensile force generator 178, protrusion 186 preventstensile force generator 178 from passing over first joint 151. Torque280 remains substantially zero since the force of the constrainedtensile force generator 178 is substantially centered about first joint151. First angle 193 being greater than toggle angle 195 corresponds tosituations where person 200 intends to rest his/her upper arm 204 athis/her sides, or pick a tool from his/her tool belt. In thesesituations, a substantially small torque 280 is desired to allow freemotion of upper arm 204 of person or to allow upper arm 204 to restwithout the impedance of torque 280. This creates a greater overallcomfort of person 200 during non-working postures. FIG. 54 depicts anembodiment wherein protrusion 186 is formed by first joint pin 184forming first joint 151. FIG. 55 depicts an embodiment whereinprotrusion 186 is a part of proximal link 150.

FIG. 56 depicts a graph of torque 280 created by torque generator 108 asa function of first angle 193 without protrusion 186. At toggle angle195, torque 280 becomes negative. Negative values of torque 280 mayimpede movement of upper arm 204 or decrease comfort of person 200. FIG.57 depicts a graph of torque 280 created by torque generator 108 as afunction of first angle 193 when protrusion 186 is created. When firstangle 193 becomes equal to or greater than toggle angle 195, protrusion186 constrains tensile force generator 178, ensuring that the torque 280remains substantially small (as described in FIG. 53 ). After toggleangle 195, torque 280 becomes substantially zero, creating neutral zone197 for the remainder of first angle 193. Neutral zone 197 allows upperarm 204 of person 200 to move with a substantially zero applied torque280 within first angle 193 greater than toggle angle 195. Neutral zone197 allows person 200 to comfortably rest his/her upper arm in a neutralposition or to preform secondary tasks such as reaching into pockets ora tool belt.

FIG. 58 and FIG. 59 depict an embodiment of arm supporting exoskeleton100 wherein the orientation of proximal link 150 can be adjusted andheld in place relative to shoulder base 102. Proximal link offsetposition 191 is defined as the orientation of proximal link 150 relativeto gravity line 208 fixed to shoulder base 102 when person 200 isstanding upright. Proximal link offset position 191 is adjusted atoffset adjustment joint 159, which rotates substantially in the plane offirst joint 151. Toggle position 194 represents the position of distallink 152 when first joint angle 193 has become equal to toggle angle195. By adjusting proximal link offset position 191, toggle position 194is adjusted relative to shoulder base 102. Offset angle 199 representsthe angle between proximal link offset position 191 and gravity line 208when person 200 is standing upright. FIG. 58 shows an embodiment whereinoffset angle 199 is relatively small. FIG. 59 shows an embodimentwherein offset angle 199 is increased. FIG. 60 shows an explodedembodiment of arm link mechanism 104 comprising offset adjustment joint159. Offset adjustment joint 159 allows proximal link 150 to rotaterelative to shoulder base 102. Offset adjustment joint 159 can furtherlock the rotation of proximal link 150 relative to shoulder base 102 ata particular position.

FIG. 61 depicts a graph of torque 280 created by torque generator 108 asa function of angle of distal link 152 from horizon 209. Torque profile291 corresponds to a configuration when offset angle 199 is zero. Torqueprofile 292 corresponds to a configuration when offset angle 199 isfifty degrees, meaning the upward torque will not push the person's armupward unless the angle of distal link 152 is raised relative to 40degrees below horizon 209. It can be observed from this graph that onecan move the toggle position by adjusting offset angle 199. Torquegenerator offset angle 199 may be adjusted in order to position toggleposition 194 at a specific angle relative to horizon 209. Torquegenerator offset angle 199 may also be adjusted in order to create atorque profile with a specific peak position at a desired angle relativeto horizon 209. When protrusion 186 is present, neutral zone 197 isformed for both curves for angles of distal link 152 past toggleposition 194. When offset angle 199 is increased, a larger range ofneutral zone 197 is created relative to the range of motion of upper arm204.

In some embodiments, lower bracket 190, upper bracket 188, and proximallink offset position 191 can all be adjusted to create a desired supportprofile for torque 280. Arm weight torque profile 198 is defined as atorque to counter the weight of upper arm 204, forearm 206, hand 207,and tool 308. FIG. 62 depicts the profile of torque 280 where it matchesarm weight torque profile 198 in angles substantially above horizon 209and approximately cancels the arm weight torque profile 198. Overheadwelding is a good example of an activity of a person that may requiresuch torque. When the absolute angle of the distal link 152 is below −60degrees from horizon 209, the profile of torque 280 enters neutral zone197 where torque is substantially zero. This profile of torque 280 maybe created with a lower bracket 190 position or upper bracket position188 that creates torque 280 with a reduced peak amplitude compared toarm weight torque profile. Offset angle 199 may then be adjusted toshift support profile of torque 280 so that it closely matches armweight torque profile 198 for the desired range of motion. When matchedto arm weight torque profile 198, support torque 280 of reducedamplitude corresponds to a smaller range of angles in which torque 280matches arm weight torque profile 198 and a larger size of neutral zone197.

FIG. 63 depicts another support profile of torque 280 with values largerthan the arm weight torque profile 198 at some angles above horizon 209.This is useful when person 200 needs to apply an upward force greaterthan the combined weight of upper arm 204, forearm 206, hand 207, andtool 308. Drilling into a ceiling is a good example of an activity thatmay require such torque. When the absolute angle of the distal link 152is below −40 degrees from horizon 209, the profile of torque 280 entersneutral zone 197 where torque is substantially zero. This profile oftorque 280 may be created with lower bracket 190 position or upperbracket position 188 that creates torque 280 with any peak amplitudecompared to arm weight torque profile 198. Offset angle 199 may then beadjusted to shift profile of torque 280 so that it exceeds arm weighttorque profile 198 for the desired range of motion. When adjusted to armweight torque profile 198, support torque 280 of reduced amplitudecorresponds to a smaller range of angles in which torque 280 exceeds armweight torque profile 198 and a larger size of neutral zone 197.

FIG. 64 depicts another possible support profile of torque 280 withvalues substantially equal to the arm weight torque profile 198 at allangles. Manipulating a tool throughout the entire range of motion is anexample of an activity that may require such torque. This profile oftorque 280 may be created with lower bracket 190 position or upperbracket position 188 that creates torque 280 with equal peak amplitudecompared to arm weight torque profile 198. Offset angle 199 may then beadjusted to align profile of torque 280 peak with the peak of arm weighttorque profile 198. Below −90 degrees of deviation from horizon 209,torque 280 enters neutral zone 197 (not shown) where torque 280 issubstantially zero. Even with the full forward range of motionsupported, neutral zone 197 provides substantially zero torque whenupper arm 204 extends negatively behind trunk 202 of person 200, such aswhen a person's hand is reaching for a back pocket.

FIG. 65 depicts an embodiment wherein load bearing structure 112comprises back frame 130 located substantially behind person 200 andlower extremity exoskeleton 304 coupled to back frame 130 and alsocoupled to legs 228 of person 200. Back frame 130 is coupled to arm linkmechanism 104 and supports at least a portion of reaction forces 214 andreaction torques 215 from arm link mechanism 104. Back frame 130transfers at least a portion of reaction forces 214 and reaction torques215 to lower extremity exoskeleton 304. Lower extremity exoskeleton 304transfers at least a portion of reaction forces 214 and reaction torques215 to ground 310, resulting in ground reaction forces 311. Exoskeletonscan be coupled to arm supporting exoskeletons 100, in accordance withsome examples.

FIG. 66 depicts an embodiment wherein load bearing structure 112comprises a back frame 130 located substantially behind person 200 and atrunk supporting exoskeleton 302 coupled to back frame 130.

FIG. 94 depicts a perspective view of arm supporting exoskeleton 100utilizing variable force generator 401 configured to create a torqueabout first rotational joint 431 to support gravity forces on upper arm204 of person 200. In some embodiments variable force generator 401 maybe the same as tensile force generator 178 or torque generator 108, andfirst rotational joint 431 may be designed to rotate along firstrotational axis 154. Arm coupler 106 is configured to couple to upperarm 204 and is coupled to distal link 152 or first element 406. Shoulderbase 102 is configured to transfer reaction forces and torques from armcoupler 106 to trunk 202 of person 200, and is coupled to rotationalbase link 430 or proximal link 150. In some embodiments, rotational baselink 430 may the same as proximal link 150.

In one embodiment, a variable force generator creates an “on” and “off”support mode of arm supporting exoskeleton 100. In a first force mode,variable force generator 401 exhibits a substantially small firststiffness and creates a substantially small first force 402, and asubstantially small first torque 404 is applied to person's arm thatcompensates for the mass and friction of the arm supporting exoskeleton100. A substantially small first torque 404 allows free, relativelyunsupported movement of upper arm 204 of person 200. Small reactionforces and torques from first torque 404 are applied to trunk 202 ofperson through shoulder base 102 or are applied to a lower extremityexoskeleton 304 (not shown). This constitutes the off mode of armsupporting exoskeleton 100. In a second force mode, variable forcegenerator 401 exhibits a second stiffness and creates second force 403that is substantially larger than first force 402, and second torque 405substantially larger than first torque 404 is applied to upper arm 204.Second torque 405 supports upper arm 204 from gravitational forces,while reaction forces and torques from second force 403 and secondtorque 405 are applied to trunk 202 of person 200 through shoulder base102, or are applied to a lower extremity exoskeleton 304 (not shown).This constitutes the on mode of arm supporting exoskeleton 100.

In one embodiment, variable force generator creates a “high” and “low”support mode of arm supporting exoskeleton 100. In a first force mode,variable force generator 401 exhibits a first stiffness and createsfirst force 402, and first torque 404 is applied to upper arm 204, whilereaction forces and torques from first force 402 and first torque 404are applied to trunk 202 of person 200 through shoulder base 102, or areapplied to a lower extremity exoskeleton 304 (not shown). First torque404 supports upper arm 204 from gravitational forces. This constitutes alow support mode of arm supporting exoskeleton 100. In a second forcemode, variable force generator 401 exhibits a second stiffness andcreates second force 403 that is substantially larger than first force402, and second torque 405 substantially larger than first torque 404 isapplied to upper arm 204. Second torque 405 supports upper arm 204 fromgravitational forces, while reaction forces and torques from secondforce 403 second torque 405 are applied to upper trunk 202 throughshoulder base 102, or are applied to a lower extremity exoskeleton 304(not shown). This constitutes the high support mode of arm supportingexoskeleton 100.

It can be appreciated that the forces and or torques applied by variableforce generator 401 can be applied in a similar manner to a multitude ofjoints and movement mechanisms of exoskeleton, robotic, or similarapplications.

FIG. 67 shows a schematic embodiment of variable force generator 401.Variable force generator 401 is adaptable to exhibit two stiffness ratesbetween first element 406 and second element 407. In some embodiments,first element 406 may be the same as distal link 152 and second element407 may be the same as line element 182. Variable force generator 401comprises first spring 408 that has first end 409 and second end 410.First spring 408 is constrained by first element 406 from its first end409 and by the second element 407 from its second end 410. Variableforce generator 401 further comprises second spring 411 which has firstend 412 and second end 413. Second spring 411 is constrained by firstelement 406 from its first end 412. Variable force generator 401 furthercomprises at least one constraining mechanism 414 which is configurableto have at least a first position and a second position. FIG. 68 shows ahardware embodiment of variable force generator 401.

In operation, in the first force mode of variable force generator 401,the constraining mechanism 414 is in its first position as shown in FIG.69 , second end 413 of second spring 411 is not constrained by secondelement 407. This causes second spring 411 not to affect the motionbetween first element 406 and second element 407. In this first positionthe equivalent stiffness is the stiffness of first spring 408.

In the second force mode of variable force generator constrainingmechanism 414 is in its second position as shown in FIG. 70 , second end413 of second spring 411 is constrained by second element 407. Thiscauses the second spring 411 to act in parallel with first spring 408.In this second position, the equivalent stiffness is the addition ofboth the stiffness of first spring 408 and stiffness of second spring411.

In some embodiments, the stiffness of first spring 408 is substantiallysmaller than the stiffness of second spring 411. When constrainingmechanism 414 is in its first position, the motion between first element406 and second element 407 generates a substantially small force betweenfirst element 406 and second element 407 relative to the force generatedwhen constraining mechanism 414 is in its second position.“Substantially small force” is defined as just enough force to overcomethe mass and or friction associated with the movement of variable forcegenerator 401. With a substantially small force applied, variable forcegenerator 401 appears to be off, or free moving, to an observer, withlittle to no spring force discernable. When constraining mechanism 414is in its second position, the motion between first element 406 andsecond element 407 generates a force between first element 406 andsecond element 407 roughly equivalent to the stiffness of second spring411.

FIG. 68 , FIG. 69 , and FIG. 70 show an embodiment wherein first spring408 further comprises first spring element 442 and first spring bracket415. First spring element 442 provides the stiffness of first spring408. First spring element 442 may take the form of a coil spring asshown in all figures, or the form of a gas spring, rubber, or any othertype of resilient element with an associated stiffness. First springbracket 415 serves to facilitate the housing, motion, or generalfunction of constraining mechanism 414 between its first position andsecond position. First spring bracket 415 may be located at first end409 or second end 410 of the first spring 408. First spring bracket 415may further facilitate the coupling of first spring 408 to secondelement 407. First spring bracket 415 may further facilitate the motionor stabilization of first spring 408 while it is undergoing compressionor extension. First spring bracket 415 transfers force between firstspring 442 and second element 407. First spring bracket 415 alsotransfers force between constraining mechanism 414 and second element407 when constraining mechanism 414 is in its second position.

FIG. 68 , FIG. 69 , and FIG. 70 show an embodiment wherein second spring411 further comprises second spring element 443 and second springbracket 416. Second spring element 443 provides the stiffness of secondspring 411. Second spring element 443 may take the form of a coil springas shown in all figures, or the form of a gas spring, rubber, or anyother type of resilient element with an associated stiffness. Secondspring bracket 416 serves to facilitate the housing, motion, or generalfunction of constraining mechanism 414 between its first position andsecond position. Second spring bracket 416 may be located at the firstend 412 or second end 413 of second spring 411. Second spring bracket416 may further facilitate the motion or stabilization of second spring411 while it is undergoing compression or extension. Second springbracket 416 transfers force between second spring element 443 andconstraining mechanism 414 when constraining mechanism 414 is in itssecond position.

FIG. 69 and FIG. 70 show an embodiment of variable force generator 401configured to create a tensile force between first element 406 andsecond element 407. To generate a tensile force, second element 407 maybe made of a rigid, semi-rigid, or flexible material. In someembodiments, second element 407 comprises a flexible steel cable.

FIG. 69 shows variable force generator 401 wherein constrainingmechanism 414 is in a first position. Second end 413 of second spring411 is not constrained by second element 407. Therefore, second spring411 does not affect the motion between first element 406 and secondelement 407. In this first position, the equivalent stiffness is thestiffness of first spring 408, and variable force generator 401 producesfirst force 402 between first element 406 and second element 407 that istensile.

FIG. 70 shows variable force generator 401 wherein constrainingmechanism 414 is in a second position. Second end 413 of second spring411 is constrained by second element 407. This causes the second spring411 to act in parallel with first spring 408. In this second position,the equivalent stiffness is the addition of both the stiffness of firstspring 408 and stiffness of second spring 411, and variable forcegenerator 401 produces second force 403 between first element 406 andsecond element 407 that is tensile.

FIG. 71 shows an embodiment of variable force generator 401 configuredto create a compressive force between first element 406 and secondelement 407 through a re-arrangement of components. Second element 407may be made of a rigid or semi-rigid material in order to generate acompressive force.

In FIG. 71 , constraining mechanism 414 is in a first position. Secondend 413 of second spring 411 is not constrained by second element 407,so second spring 411 does not affect the motion between first element406 and second element 407. In this first position, the equivalentstiffness is the stiffness of first spring 408, and variable forcegenerator 401 produces a first force 402 between first element 406 andsecond element 407 that is compressive. It can be understood by oneskilled in the art that the force produced by any embodiment herein maybe made compressive by a similar re-arrangement of components.

FIG. 72 and FIG. 73 show a radial section of an embodiment wherein firstspring 408 and second spring 411 are arranged concentrically. FIG. 72shows variable force generator 401 wherein constraining mechanism 414 isin a first position. FIG. 73 shows variable force generator 401 whereinconstraining mechanism 414 is in a second position.

In the embodiment of FIG. 72 and FIG. 73 , second element 407 isarranged concentrically with one or a combination of the first spring408, second spring 411, or first element 406.

In the embodiment of FIG. 72 and FIG. 73 , first element 406 comprises acylindrical opening. First spring 408 and second spring 411 are arrangedconcentrically within the cylindrical first element 406 whileconstrained by the cylindrical first element 406 from their respectivefirst ends 409 and 412.

FIG. 72 and FIG. 73 depict a radial section of variable force generator401 further comprising orientation sleeve 417. Orientation sleeve 417 isconfigured to radially constrain first spring 408 relative to secondspring 411. The radial constraint may be used to facilitate smoothmotion or a bearing surface, or to prevent contact between coils offirst spring 408 and second spring 411.

FIG. 74 , FIG. 75 , FIG. 76 , and FIG. 77 depict a detailed axialsection view of variable force generator 401. Variable force generator401 may further comprise one or more rotational orientation elementsthat rotationally constrain first spring 408, second spring 411,orientation sleeve 417, or any combination thereof relative to firstelement 406. In the embodiment of FIG. 74 , first orientation element418 rotationally constrains orientation sleeve 417 relative to firstelement 406 by means of a pin, although other configurations arepossible. Additionally, second orientation element 419 rotationallyconstrains orientation sleeve 417 relative to first spring bracket 415by means of a pin, although other configurations are possible.

In some embodiments, orientation sleeve 417 is configured to radiallyconstrain second spring 411 relative to first element 406. The radialconstraint may be used to facilitate smooth motion or a bearing surface,or to prevent contact between coils of second spring 411 and firstelement 406.

In some embodiments first element 406 acts to radially constrain secondspring 411. In still other embodiments, second element 407 acts toradially constrain first spring 408.

In some embodiments, a number of rotational orientation elements may beused to rotationally constrain first spring 408 and or second spring 411relative to first element 406. Rotational constraints may be necessaryto ensure proper positioning of components for the function ofconstraining mechanism 414 to move between its first position and secondposition. FIG. 72 shows an embodiment where constraining mechanism 414further serves to rotationally constrain second spring 411 relative tofirst element 406 and or orientation sleeve 417 when constrainingmechanism 414 is in its first position.

FIG. 73 shows an embodiment wherein constraining mechanism 414 furtherserves to rotationally constrain second spring 411 relative to firstspring 408 or orientation sleeve 417 when constraining mechanism 414 isin its second position.

FIG. 74 depicts an embodiment of variable force generator 401 thatcomprises one or more axial orientation elements that axially constrainfirst spring 408, second spring 411, orientation sleeve 417, or anycombination thereof to first element 406. Axial constraint of firstspring 408 and second spring 411 relative to first element 406 serves toremove any forces on constraining mechanism 414 due to the stiffness offirst spring 408 or second spring 411. Removing forces on constrainingmechanism 414 allows for an easier transition between its first positionand second position.

In embodiment shown in FIG. 74 , first orientation element 418 axiallyconstrains orientation sleeve 417, relative to first element 406.Furthermore, first orientation element 418 axially constrains themaximum extension of first spring 408 and second spring 411 relative tofirst element 406 by means of a pin, although other configurations arepossible

In another embodiment, second orientation element 419 axially constrainsorientation sleeve 417 relative to first spring 408 by means of a pinand slot configuration, although other configurations are possible.

The axial position of first orientation element 418 and secondorientation element 419 may further be used to preload first spring 408and or second spring 411 when axially constrained by first orientationelement 418 or second orientation element 419. The amount of preload offirst spring 408 and or second spring 411 may be manipulated to alterthe forces generated by variable force generator 401.

In some embodiments, variable force generator 401 further comprisespreload element 426. Preload element 426 axially constrains first spring408 and or second spring 411 relative to first element 406 to preloadfirst spring 408 and or second spring 411 when axially constrainedagainst first orientation element 418 and or second orientation element419. When axially constrained against first orientation element 418,preload element 426 may preload first spring 408 by a different distancethan second spring 411. The amount of preload provided by preloadelement 426 may be used to alter the force profile of variable forcegenerator 401, allow for the use of varying types and or lengths offirst spring 408 and or second spring 411, or facilitate properpositioning of components.

In some embodiments, the axial length of first spring bracket 415 and orsecond spring bracket 416 act to preload first spring element 442 and orsecond spring element 443 when axially constrained against firstorientation element 418 and or second orientation element 419

In some embodiments, constraining mechanism 414 is translationallycoupled to second spring 411. FIG. 72 through FIG. 77 show an embodimentof variable force generator 401 wherein constraining mechanism 414 is apin or t-pin that slides though a hole within second spring 411.Constraining mechanism 414 is configured to slide into a profile, suchas a hole or slot, within first spring 408 when constraining mechanism414 is in its second position. When the constraining mechanism 414 hasslid into the hole of first spring 408, the result is that second spring411 is axially coupled to first spring 408, and thus second element 407,allowing stiffness from both first spring 408 and second spring 411 tobe transferred between first element 406 and second element 407.

FIG. 78 is a radial section view of an alternative embodiment ofvariable force 401 wherein constraining mechanism 414 is a retainingring translationally coupled to second spring 411 and configured to lockinto a groove on first spring 408 and therefore axially couple firstspring 408 to second spring 411.

In another embodiment (not shown) constraining mechanism 414 maysimilarly be translationally coupled to first spring 408 and slide intoa profile, such as a hole or slot, in second spring 411.

FIG. 79 is an axial section view of an alternative embodiment ofvariable force generator 401 wherein constraining mechanism 414 isrotatably coupled to second spring 411. In its second position,constraining mechanism 414 is configured to couple to a profile in thefirst spring 408 and therefore axially couple second spring 411 to firstspring 408 or second element 407. When constraining mechanism 414 is inits second position, stiffness from both first spring 408 and secondspring 411 is transferred between first element 406 and second element407.

FIG. 80 is an axial section view of an embodiment of variable forcegenerator 401 wherein constraining mechanism 414 is rotatably coupled tofirst spring 408. In its second position, constraining mechanism 414 isconfigured to couple to a profile in the second spring 411 and thereforeaxially couple second spring 411 to first spring 408 or second element407. When constraining mechanism 414 is in its second position,stiffness from both first spring 408 and second spring 411 istransferred between first element 406 and second element 407.

FIG. 81 is an axial section view of an alternative embodiment ofvariable force 401 wherein constraining mechanism 414 comprises a pintranslationally coupled to second spring 411 that can be selectivelycoupled to a hook that is coupled to or part of first spring 408. Whenconstraining mechanism 414 is in its first position, it cannot couple tothe hook. When constraining mechanism 414 is in its second position asshown, it can couple with the hook and therefore axially couple firstspring 408 to second spring 411. In another embodiment (not shown), thepin can be rotatably coupled to second spring 411 or the pin and hookcombination can be reversed between first spring 408 and second spring411.

FIG. 82 shows a radial section view of an embodiment of variable forcegenerator 401 wherein the function of constraining mechanism 414 isembedded in the shape and rotational orientation of second spring 411relative to first spring 408. In the embodiment, first spring 408comprises a number of protrusions and second spring 411 comprises anumber of profiles allowing the protrusions of first spring 408 to passthrough. When the protrusions of first spring 408 and profiles of secondspring 411 are aligned, constraining mechanism 414 is in its firstposition and second spring 411 is not coupled to first spring 408. Whensecond spring 411 is rotated so that the protrusions of first spring 408and profiles of second spring 411 are not aligned, constrainingmechanism 414 is in its second position and first spring 408 is axiallycoupled to second spring 411. In another embodiment (not shown), theprotrusions are on second spring 411 and the profiles are on firstspring 408.

FIG. 83 shows an axial section view of an embodiment of variable forcegenerator 401 wherein the function of constraining mechanism 414 isembedded into the first spring 408 and second spring 411. First spring408 and second spring 411 each comprise mating threads that allow firstspring 408 to be axially coupled to second spring 411 when either isrotated in a manner that engages the threads. FIG. 83 shows theconstraining mechanism 414 in a second position wherein the threadsbetween first spring 408 and second spring 411 are engaged. The firstposition of constraining mechanism 414 would correspond to no threadsbetween first spring 408 and second spring 411 being engaged.

FIG. 84 shows a radial section view of an embodiment of variable forcegenerator 401 wherein constraining mechanism 414 is a screw or cam thatcauses second spring 411 to clamp, or friction lock, with first springbracket 408. When constraining mechanism 414 is in its first position,the screw or cam is loose and first spring 408 can freely pass in andout of second spring 411. When constraining mechanism 414 is in itssecond position, the screw or cam is tightened and first spring 408 iscompressed within second spring 411. This feature couples first spring408 to second spring 411 allowing the stiffness of second spring 411 tobe transferred between first element 406 and second element 407.

It can be appreciated by one skilled in the art that all of theembodiments of constraining mechanism 414 presented herein can beapplied to other spring arrangements described later in this text toconstrain any combination of first spring 408, second spring 411, firstelement 406, or second element 407

In the embodiment shown in FIG. 74 through FIG. 77 , first springbracket 415 has a profile that when first spring bracket 415 is notconstrained to second spring bracket 416, the first spring bracket 415profile moves constraining mechanism 414 out of the way of first springbracket 415 (i.e., into first position), allowing first spring bracket415 to reach the transition position. In the first embodiment, firstspring bracket 415 has a chamfered profile but it can be appreciatedthat other profiles are possible to reach similar results.

In some embodiments constraining mechanism 414 is made of a magneticmaterial.

In the embodiment shown in FIG. 74 through FIG. 77 , variable forcegenerator 401 further comprises at least one first magnet 422 coupled tofirst spring 408 that attracts constraining mechanism 414 into itssecond position when first spring 408 and second spring 411 are properlyaligned with first element 406. When first magnet 422 attractsconstraining mechanism 414, it thereby axially and/or rotationallycouples first spring 408 to second spring 411.

In the embodiment shown in FIG. 74 through FIG. 77 , variable forcegenerator 401 further comprises at least one second magnet 423 coupledto first element 406 that attracts constraining mechanism 414 into itsfirst position when first spring 408 and second spring 411 are properlyaligned to first element 406. When second magnet 423 attractsconstraining mechanism 414, it thereby decouples first spring 408 fromsecond spring 411.

In some embodiments, the influence of second magnet 423 on constrainingmechanism 414 is stronger than the influence of first magnet 422 onconstraining mechanism 414. When first spring 408 and second spring 411are properly positioned relative to first element 406, constrainingmechanism 414 will automatically enter a first position.

In the embodiment shown in FIG. 74 through FIG. 77 , variable forcegenerator 401 further comprises switch 420 coupled to at least onesecond magnet 423 and translationally coupled to first element 406. Inanother embodiment (not shown), switch 420 may be rotatably coupled forfirst element 406. Switch 420 can be moved relative to first element 406between a first position wherein the second magnet 423 does attract theconstraining mechanism 414 to a second position wherein the secondmagnet 423 does not attract the constraining mechanism 414.

FIG. 74 shows variable force generator 401 at the transition positionwherein switch 420 is in its second position. Second magnet 423 does nothave influence on constraining mechanism 414; thus, first magnet 422attracts constraining mechanism 414 to its second position and causes itto couple first spring 408 to second spring 411. Switch 420 can be movedto its second position for any position of first spring 408 and secondspring 411, and when first spring 408 and second spring 411 return tothe transition position, constraining mechanism 414 will move it itssecond position.

FIG. 75 shows variable force generator 401 at the transition positionwherein switch 420 is in its first position. Second magnet 423 attractsconstraining mechanism 414 to its first position and causes it todecouple first spring 408 from second spring 411. Switch 420 can bemoved to its first position for any position of first spring 408 andsecond spring 411, and when first spring 408 and second spring 411return to the transition position, constraining mechanism 414 will moveit its first position. In some embodiments first element 406 furthercomprises cover 421 for switch 420.

FIG. 85 shows another embodiment of variable force generator 401 whereinswitch 420 further comprises a holding magnet 453. The influence ofholding magnet 453 on constraining mechanism 414 is weaker than theinfluence of first magnet 422 on constraining mechanism 414. Thus, whenboth the holding magnet 453 and first magnet 422 are exposed toconstraining mechanism 414, constraining mechanism 414 will transitionto a second position. Holding magnet 453 is exposed to constrainingmechanism 414 when switch 420 is at a second position. Holding magnet453 holds constraining mechanism 414 out of the way of first spring 408,allowing first spring 408 to reach a transition position. Thus whenfirst spring 408 reaches the transition position, constraining mechanism414 will automatically move to its second position.

FIG. 86 shows an embodiment wherein constraining mechanism 414 houses athird magnet 444 and wherein switch 420 comprises fourth magnet 445 andfifth magnet 446. Fourth magnet 445 is configured to attract thirdmagnet 444 housed in constraining mechanism 414. When switch 420 ispositioned so that fourth magnet 445 attracts third magnet 444,constraining mechanism 414 moves to a first position wherein first 408is decoupled from second spring 411. Fifth magnet 446 is configured torepel third magnet 444 housed in constraining mechanism 414. When switch420 is positioned so that fifth magnet 446 repels third magnet 444,constraining mechanism 414 moves to a second position wherein firstspring 408 is coupled to second spring 411.

It can be appreciated by one skilled in the art that for any of theembodiments herein, the movement of constraining mechanism 414 relativeto first spring 408 or second spring 411 may be similarly biased by aspring to cause constraining mechanism 414 to move to a first positionor a second position.

FIG. 87 shows an embodiment of variable force generator 401 furthercomprising wedge element 429. Wedge element 429 forces constrainingmechanism 414 into a second position in the event that constrainingmechanism 414 is caught between first and second position and istherefore coupling first element 406 to second element 407. Thisprevents variable force generator 401 from locking first element 406 tosecond element 407.

FIG. 88 shows an embodiment of variable force generator 401 whereinwedge element 429 is a contoured surface of constraining mechanism 414.

FIG. 89 depicts an axial section view of variable force generator 401configured to create a torque about first rotational joint 431. Firstrotational joint 431 is formed between first element 406 and rotationalbase link 430. In the embodiment, variable force generator 401 furthercomprises pulley 432 attached to first element 406 that routes flexiblesecond element 407 to a rotational coupling with rotational base link430. In the embodiment shown, constraining mechanism 414 is in a firstposition wherein first spring 408 is decoupled from second spring 411.First force 402 is created between first element 406 and second element407 and thus first torque 404 is created between first element 406 androtational base link 430 about first rotational joint 431.

FIG. 90 depicts variable force generator 401 of FIG. 76 whereinconstraining mechanism 414 is in its second position and wherein firstspring 408 is coupled to second spring 411. A second force 403 iscreated between first element 406 and second element 407 and thus secondtorque 405 is created between first element 406 and rotational base link430 about first rotational joint 431.

When the proper position (radially, axially, and/or rotationally) isachieved between first spring 408, second spring 411, and first element406, a transition position is achieved wherein there are no forcesacting on constraining mechanism 414. This allows constraining mechanism414 to more easily transition variable force generator 401 between firstforce mode and second force mode.

FIG. 72 , FIG. 73 , FIG. 74 , and FIG. 75 show variable force generator401 in transition position wherein all forces acting on constrainingmechanism 414 due to first spring 408 and or second spring 411facilitate ease of motion of constraining mechanism 414. FIG. 73 andFIG. 74 show constraining mechanism 414 is in its second position. FIG.72 and FIG. 75 show constraining mechanism 414 in its first position.

FIG. 92 depicts variable force generator 401 of FIG. 89 and FIG. 90 atthe transition position, resulting in transition angle 427 between firstelement 406 and rotational base link 430. When an angle of first element406 relative to rotational base link 430 is smaller than firsttransition angle 427, flexible second element 407 goes slack andvariable force generator 401 does not generate a force or torque aboutfirst rotational joint 431. When an angle of first element 406 relativeto rotational base link 430 is larger than first transition angle 427,variable force generator 401, depending on the position of constrainingmechanism 414, generates either first force 402 and thus first torque404 or second force 403 and thus second torque 405.

In some embodiments, it is possible to change the length of secondelement 407 by means of its coupling to first spring 408. In theembodiment of FIGS. 92 and 93 , this is done by threaded end 425 onsecond element 407 meshing with a female thread on first spring bracket415.

FIG. 93 depicts variable force generator 401 of FIG. 89 at thetransition position. The length of second element 407 has been increasedrelative to FIG. 92 resulting in a larger transition angle 427. It canbe appreciated by one skilled in the art that the length of secondelement 407 may be increased or decreased to increase or decrease thetransition angle 427.

In other embodiments (not shown), second element 407 may have a similarscrew connection with rotational base link 430 to achieve the sameadjustment to transition angle 427. In still other embodiments, secondelement 407 may comprise the ability to change length, such as with aturnbuckle, without an adjustable connection to first spring 408 orrotational base link 430 to achieve the same adjustment to transitionangle 427.

FIG. 91 depicts an axial section view of an alternative embodiment ofvariable force generator 401 configured to create a torque about firstrotational joint 431 formed between first rotating link 434 androtational base link 430. First element 406 is rotatably and/ortranslationally coupled to first rotating link 434, and second element407 is rotationally and/or translationally coupled to rotational baselink 430. In the embodiment shown, constraining mechanism 414 is in itssecond position wherein first spring 408 is coupled to second spring411. Second force 403 is created between first element 406 and secondelement 407 and thus second torque 405 is created between first element406 and rotational base link 430 about first rotational joint 431.

In some embodiments, variable force generator 401 may be mounted to theshoulder base 102 of arm supporting exoskeleton 100 and transfer forcesto the arm link mechanism 104 by means of control cables. This be doneto move the mass of the arm supporting exoskeleton 100 as close to thetorso as possible. The control cables may be situated as to not inhibitmotion of the arm link mechanism 104 or shoulder base 102.

FIG. 101 shows a schematic embodiment of variable force generator 401designed to utilize extension springs rather than compression springs aspreviously shown. Variable force generator 401 is adaptable to exhibittwo stiffness rates between first element 406 and second element 407.Variable force generator 401 comprises first spring 408 that has firstend 409 and second end 410. First spring 408 is constrained by firstelement 406 from its first end 409 and by the second element 407 fromits second end 410. Variable force generator 401 further comprisessecond spring 411 which has first end 412 and second end 413. Secondspring 411 is constrained by second element 407 from its second end 413.Variable force generator 401 further comprises at least one constrainingmechanism 414 which is configurable to have at least a first positionand a second position. FIG. 102 shows a hardware embodiment of variableforce generator 401.

In operation, when the constraining mechanism 414 is in its firstposition, as shown in FIG. 103 , first end 412 of second spring 411 isnot constrained by first element 406. This causes second spring 411 notto affect the motion between first element 406 and second element 407.In this first position, the equivalent stiffness is the stiffness offirst spring 408.

When constraining mechanism 414 is in its second position as shown inFIG. 102 , first end 412 of second spring 411 is constrained by firstelement 406. This causes the second spring 411 to act in parallel withfirst spring 408. In this second position, the equivalent stiffness isthe addition of both the stiffness of first spring 408 and stiffness ofsecond spring 411.

FIG. 102 and FIG. 103 depict a translational coupling arrangement ofconstraining mechanism 414 between second spring 411 and first element406 similar in function to the embodiment of FIG. 68 , the onlydifference being between the two components constrained by constrainingmechanism 414.

FIG. 104 depicts a pin and hook arrangement of constraining mechanism414 between second spring 411 and first element 406 similar in form tothe embodiment of FIG. 81 , the only difference being between the twocomponents constrained by constraining mechanism 414.

FIG. 105 depicts a rotatable coupling arrangement of constrainingmechanism 414 between second spring 411 and first element 406 similar inform to the embodiment of FIG. 80 , the only difference being betweenthe two components constrained by constraining mechanism 414.

It can be appreciated by one skilled in the art that all of theembodiments of constraining mechanism 414 presented herein can beapplied to other spring arrangements described later in this text toconstrain any combination of first spring 408, second spring 411, firstelement 406, or second element 407.

FIG. 106 shows a schematic embodiment of variable force generator 401utilizing first spring 408 and second spring 411 in series. Variableforce generator 401 is adaptable to exhibit two stiffness rates betweenfirst element 406 and second element 407. Variable force generator 401comprises first spring 408 that has first end 409 and second end 410.First spring 408 is constrained by first element 406 from its first end409 and by the second spring 411 from its second end 410. Variable forcegenerator 401 further comprises second spring 411, which has first end412 and second end 413. Second spring 411 is constrained by first spring408 from its first end 412 and by second element 407 from its secondend. Variable force generator 401 further comprises at least oneconstraining mechanism 414, which is configurable to have at least afirst position and a second position. FIG. 107 shows a hardwareembodiment of this embodiment of variable force generator 401.

In operation, when the constraining mechanism 414 is in its firstposition, first end 412 of second spring 411 is not constrained by firstelement 406. This causes second spring 411 to act in series with firstspring 411. In this first position, the equivalent stiffness is thestiffness of first spring 408 and second spring 411 in series. In thisfirst position, the equivalent deflection is the deflection of firstspring 408 and second spring 411 in series. When constraining mechanism414 is in its second position, first end 412 of second spring 411 isconstrained by first element 406. This causes the second spring 411 toact alone. In this second position, the equivalent stiffness is thestiffness of second spring 411, and the equivalent deflection is thedeflection of second spring 411. In the series combination shown, firstspring 408 or second spring 411 may be compression or extension springs.

FIG. 108 shows an alternative embodiment of variable force generator 401with first spring 408 and second spring 411 in series. Variable forcegenerator 401 is adaptable to exhibit two stiffness rates between firstelement 406 and second element 407. Variable force generator 401comprises first spring 408 that has first end 409 and second end 410.First spring 408 is constrained by second spring 411 from its first end409 and by the second element 407 from its second end 410. Variableforce generator 401 further comprises second spring 411, which has firstend 412 and second end 413. Second spring 411 is constrained by firstelement 406 from its first end 412 and by first spring 408 from itssecond end 413. Variable force generator 401 further comprises at leastone constraining mechanism 414, which is configurable to have at least afirst position and a second position.

In operation, when the constraining mechanism 414 is in its firstposition, second end 413 of second spring 411 is not constrained bysecond end 410 of first spring 408. This causes second spring 411 to actin series with first spring 408. In this first position, the equivalentstiffness is the stiffness of first spring 408 and second spring 411 inseries. In this first position, the equivalent deflection is thedeflection of first spring 408 and second spring 411 in series. Whenconstraining mechanism 414 is in its second position, second end 413 ofsecond spring 411 is constrained by second end 410 of first spring 408.This causes the second spring 411 to act alone. In this second position,the equivalent stiffness is the stiffness of second spring 411, and theequivalent deflection is the deflection of second spring 411.

FIG. 109 shows an alternative embodiment of variable force generator 401with first spring 408 and second spring 411 in series. Variable forcegenerator 401 is adaptable to exhibit two stiffness rates between firstelement 406 and second element 407. Variable force generator 401comprises first spring 408 that has first end 409 and second end 410.First spring 408 is constrained by second spring 411 from its first end409 and by the second element 407 from its second end 410. Variableforce generator 401 further comprises second spring 411, which has firstend 412 and second end 413. Second spring 411 is constrained by firstelement 406 from its first end 412 and by first spring 408 from itssecond end 413. Variable force generator 401 further comprises at leastone constraining mechanism 414, which is configurable to have at least afirst position and a second position.

In operation, when the constraining mechanism 414 is in its firstposition, second end 413 of second spring 411 is not constrained byfirst element 406. This causes second spring 411 to act in series withfirst spring 411. In this first position, the equivalent stiffness isthe stiffness of first spring 408 and second spring 411 in series. Inthis first position, the equivalent deflection is the deflection offirst spring 408 and second spring 411 in series. When constrainingmechanism 414 is in its second position, second end 413 of second spring411 is constrained by first element 406. This causes the first spring408 to act alone. In this second position, the equivalent stiffness isthe stiffness of first spring 408, and the equivalent deflection is thedeflection of first spring 408.

FIG. 110 shows a schematic embodiment of a variable force generator 401utilizing first spring 408 and second spring 411 in series. Variableforce generator 401 is adaptable to exhibit two stiffness rates betweenfirst element 406 and second element 407. Variable force generator 401comprises first spring 408 that has first end 409 and second end 410.First spring 408 is constrained by first element 406 from its first end409 and by the second spring 411 from its second end 410. Variable forcegenerator 401 further comprises second spring 411, which has first end412 and second end 413. Second spring 411 is constrained by first spring408 from its first end 412 and by second element 407 from its secondend. Variable force generator 401 further comprises at least oneconstraining mechanism 414, which is configurable to have at least afirst position and a second position.

In operation, when the constraining mechanism 414 is in its firstposition, second end 413 of second spring 411 is not constrained bysecond end 410 of first spring 408. This causes second spring 411 to actin series with first spring 411. In this first position, the equivalentstiffness is the stiffness of first spring 408 and second spring 411 inseries. In this first position, the equivalent deflection is thedeflection of first spring 408 and second spring 411 in series.

When constraining mechanism 414 is in its second position, second end413 of second spring 411 is constrained by second end 410 of firstspring 408. This causes the first spring 408 to act alone. In thissecond position, the equivalent stiffness is the stiffness of firstspring 408, and the equivalent deflection is the deflection of firstspring 408.

FIG. 95 shows a schematic embodiment of variable force generator 401.Variable force generator 401 is adaptable to exhibit three stiffnessrates between first element 406 and second element 407. Variable forcegenerator 401 comprises first spring 408 that has a first end 409 andsecond end 410. First spring 408 is constrained by first element 406from its first end 409 and by the second element 407 from its second end410. Variable force generator 401 further comprises two second springs411 which have first end 412 and second end 413. Second springs 411 areconstrained by first element 406 from their first end 412. Variableforce generator 401 further comprises at least two constrainingmechanisms 414 which are configurable to have at least a first positionand a second position. FIG. 96 shows a hardware embodiment of variableforce generator 401.

In operation, when both constraining mechanisms 414 are in their firstposition, second end 413 of both second springs 411 are not constrainedby second element 407. This causes second springs 411 not to affect themotion between first element 406 and second element 407. In this firstposition, the equivalent stiffness is the stiffness of first spring 408.When one constraining mechanism 414 is in its second position and oneconstraining mechanism 414 is in its first position, second end 413 ofone second spring 411 is constrained by second element 407 and secondend 413 of the other second spring 411 is not constrained by secondelement 407. This causes one second spring 411 to act in parallel withfirst spring 408. In this second position, the equivalent stiffness isthe addition of both the stiffness of first spring 408 and stiffness ofone second spring 411. When both constraining mechanisms 414 are intheir second position, second end 413 of both second springs 411 areconstrained by second element 407. This causes both second springs 411to act in parallel with first spring 408. In this second position, theequivalent stiffness is the addition of both the stiffness of firstspring 408 and stiffness of both second springs 411.

It may be appreciated by one skilled in the art that a greater number ofsecond springs 411 may be added to increase the number of stiffnessrates between first element 406 and second element 407.

FIG. 97 shows a schematic embodiment of variable force generator 401.Variable force generator 401 is adaptable to exhibit three stiffnessrates between first element 406 and second element 407. Variable forcegenerator 401 comprises first spring 408 that has a first end 409 andsecond end 410. First spring 408 is constrained by first element 406from its first end 409 and by the second element 407 from its second end410. Variable force generator 401 further comprises second spring 411,which has first end 412 and second end 413. Second spring 411 isconstrained by first element 406 from its first end 412. Variable forcegenerator further comprises third spring 447 which has first end 448 andsecond end 449. Third spring 447 is constrained by first element 406from its first end 448. Variable force generator 401 further comprisesconstraining mechanism 414, which is configurable to have at least afirst position and a second position. Variable force generator furthercomprises a second constraining mechanism 452, which is configurable tohave at least a first position and a second position.

FIG. 98 shows a hardware embodiment of variable force generator 401wherein first spring 408 further comprises first spring element 442 andfirst spring bracket 415, second spring 411 further comprises secondspring element 443 and second spring bracket 416, and third spring 447further comprises third spring element 450 and third spring bracket 451.The function of each spring element is to provide the stiffness of therespective spring. The function of each spring bracket is to transferforce, facilitate the housing, motion, or general function ofconstraining mechanism 414 or second constraining mechanism 452,facilitate the coupling between components, or facilitate the motion orstabilization of its respective spring.

In operation, when constraining mechanism 414 is in its first position,second end 413 of second spring 411 and of third spring 447 are notconstrained by second element 407. This causes second spring 411 andthird spring 447 not to affect the motion between first element 406 andsecond element 407. In this first position, the equivalent stiffness isthe stiffness of first spring 408. When constraining mechanism 414 is inits second position and second constraining mechanism 452 is in itsfirst position, second end 413 of second spring 411 is constrained bysecond element 407 and second end 413 of third spring 447 is notconstrained by second element 407. This causes second spring 411 to actin parallel with first spring 408. In this second position, theequivalent stiffness is the addition of both the stiffness of firstspring 408 and stiffness of one second spring 411. When constrainingmechanisms 414 and second constraining mechanism 452 are in their secondpositions, second end 413 of second springs 411 and of third spring 447are constrained by second element 407. This causes second spring 411 andthird spring 447 to act in parallel with first spring 408. In thissecond position, the equivalent stiffness is the addition of thestiffness of first spring 408 the stiffness of second springs 411, andthe stiffness of third spring 447.

FIG. 99 shows a schematic embodiment of variable force generator 401.Variable force generator 401 is adaptable to exhibit three stiffnessrates between first element 406 and second element 407. Variable forcegenerator 401 comprises first spring 408 that has first end 409 andsecond end 410. First spring 408 is constrained by first element 406from its first end 409 and by the second element 407 from its second end410. Variable force generator 401 further comprises second spring 411,which has first end 412 and second end 413. Second spring 411 isconstrained by first element 406 from its first end 412. Variable forcegenerator further comprises third spring 447, which has first end 448and second end 449. Third spring 447 is constrained by first element 406from its first end 448. Variable force generator 401 further comprisesconstraining mechanism 414, which is configurable to have at least afirst position, a second position, and a third position.

FIG. 100 shows a hardware embodiment of variable force generator 401wherein first spring 408 further comprises first spring element 442 andfirst spring bracket 415, second spring 411 further comprises secondspring element 443 and second spring bracket 416, and third spring 447further comprises third spring element 450 and third spring bracket 451.The function of each spring element is to provide the stiffness of therespective spring. The function of each spring bracket is to transferforce, facilitate the housing, motion, or general function ofconstraining mechanism 414, facilitate the coupling between components,or facilitate the motion or stabilization of its respective spring.

In operation, when constraining mechanism 414 is in its first position,second end 413 of second spring 411 and of third spring 447 are notconstrained by second element 407. This causes second spring 411 andthird spring 447 not to affect the motion between first element 406 andsecond element 407. In this first position, the equivalent stiffness isthe stiffness of first spring 408. When constraining mechanism 414 is inits second position, second end 413 of second spring 411 is constrainedby second element 407 and second end 413 of third spring 447 is notconstrained by second element 407. This causes second spring 411 to actin parallel with first spring 408. In this second position, theequivalent stiffness is the addition of both the stiffness of firstspring 408 and stiffness of one second spring 411. When constrainingmechanisms 414 is in a third position, second end 413 of second springs411 and of third spring 447 are constrained by second element 407. Thiscauses second spring 411 and third spring 447 to act in parallel withfirst spring 408. In this third position, the equivalent stiffness isthe addition of the stiffness of first spring 408, the stiffness ofsecond springs 411, and the stiffness of third spring 447.

It can be understood that the various embodiments of spring elementarrangements and types of spring elements described can be combined toform embodiments with multiple force modes not explicitly describedherein, and that the mechanisms described herein can be modified by arearrangement of parts to selectively couple first 406, second element407, first spring 408, second spring 411, first spring bracket 415,second spring bracket 416 or any combination thereof to accomplishmultiple stiffness rates of the variable force generator 401 asdescribed in through various series and parallel spring arrangementswith compression and extension spring elements.

What is claimed is:
 1. An arm supporting exoskeleton configured to becoupled to a person to reduce shoulder forces required to raise an upperarm of the person, the arm supporting exoskeleton comprising: a distallink configured to rotate about a first rotational axis crossingapproximately through a shoulder joint of the person, an arm couplercoupled to the distal link and configured to couple the distal link toan upper arm of the person, a tensile force generator coupled to thedistal link and configured to provide a torque to flex the distal linkabout the first rotational axis thereby producing a supporting force onthe upper arm of the person, and a protrusion located substantially atthe first rotational axis, the protrusion configured to constrain thetensile force generator to prevent the tensile force generator frompassing over the first rotational axis, wherein: when the protrusiondoes not constrain the tensile force generator, the torque flexes thedistal link as a function of an angle of the distal link along a torqueprofile to support the upper arm of the person, and when the protrusionconstrains the tensile force generator, a neutral zone is created in thetorque profile that allows the upper arm of the person to move with asubstantially small applied torque.
 2. The arm supporting exoskeleton ofclaim 1, wherein the torque profile is equivalent to an arm weighttorque profile of the upper arm of the person for angles of the distallink being substantially above a horizon line.
 3. The arm supportingexoskeleton of claim 1 further comprising a bracket coupling the tensileforce generator to the distal link, wherein location of the bracket isadjustable to adjust amplitude of the torque profile.
 4. The armsupporting exoskeleton of claim 3, wherein the location of the bracketadjusts a distance corresponding to a lever arm of the tensile forcegenerator.
 5. The arm supporting exoskeleton of claim 3, wherein thelocation of the bracket does not substantially affect the neutral zoneof the torque profile.
 6. The arm supporting exoskeleton of claim 1,wherein the arm coupler further comprises: an arm cuff configured to atleast partially encircle the upper arm of the person, and an armrotation joint allowing the arm cuff to rotate relative to the distallink.
 7. The arm supporting exoskeleton of claim 1, wherein theprotrusion is configured to constrain the tensile force generator whenthe distal link rotates past a toggle angle relative to a proximal link.8. The arm supporting exoskeleton of claim 1, wherein the protrusion isa pin forming a first joint at the first rotational axis.
 9. The armsupporting exoskeleton of claim 1 further comprising a proximal linkrotatably coupled to the distal link about the first rotational axis ata first joint.
 10. The arm supporting exoskeleton of claim 9, whereinthe tensile force generator is coupled to the proximal link.
 11. The armsupporting exoskeleton of claim 10 further comprising a bracket couplingthe tensile force generator to the distal link or the proximal link,wherein location of the bracket adjusts an effective length of thetensile force generator.
 12. The arm supporting exoskeleton of claim 10further comprising a shoulder base coupled to the proximal link, whereinthe shoulder base is configured to be coupled to a trunk of the personand transfer at least a portion of a reaction force from the torque tohips of the person.
 13. The arm supporting exoskeleton of claim 12further comprising an offset adjustment joint configured to adjust andfix a position of the proximal link relative to the shoulder base aboutan axis parallel to the first rotational axis for adjusting the neutralzone or a peak torque position of the torque profile.
 14. The armsupporting exoskeleton of claim 12 further comprising at least onehorizontal rotation joint configured to allow the proximal link torotate relative to the shoulder base about a second rotational axis. 15.The arm supporting exoskeleton of claim 1, wherein: the tensile forcegenerator comprises at least one line element selected from the groupconsisting of a wire rope, a rope, a cable, a twine, a strap, a chain,or any combination thereof, and the protrusion constrains the at leastone line element.
 16. The arm supporting exoskeleton of claim 1,wherein: the tensile force generator comprises a plurality of springelements, and at least one of the plurality of spring elements isconfigured to be activated individually or collectively.
 17. An armsupporting exoskeleton configured to be coupled to a person to reduceshoulder forces required to raise an upper arm of the person, the armsupporting exoskeleton comprising: a distal link configured to rotateabout a first rotational axis crossing approximately through a shoulderjoint of the person, and a tensile force generator coupled to the distallink and configured to provide a torque to flex the distal link aboutthe first rotational axis, and a protrusion located substantially at thefirst rotational axis and configured to constrain the tensile forcegenerator in a position substantially centered about the firstrotational axis, wherein: the torque flexes the distal link when theprotrusion does not constrain the tensile force generator, and thetorque remains substantially small when the protrusion constrains thetensile force generator.
 18. The arm supporting exoskeleton of claim 17further comprising a bracket coupling the tensile force generator to thedistal link, wherein location of the bracket is adjustable to adjust thetorque.
 19. The arm supporting exoskeleton of claim 18, wherein thelocation of the bracket adjusts a lever arm of the tensile forcegenerator.
 20. The arm supporting exoskeleton of claim 17 furthercomprising an arm coupler, configured to couple the distal link to theupper arm of the person, wherein: the arm coupler is configured to applythe torque as a supporting force to the upper arm of the person therebyreducing forces required to raise the upper arm of the person, and whenthe torque remains substantially small the person is able move the upperarm freely.
 21. The arm supporting exoskeleton of claim 17, wherein theprotrusion is configured to constrain the tensile force generator whenthe distal link rotates past a toggle angle relative to a proximal link.22. The arm supporting exoskeleton of claim 17 further comprising aproximal link, wherein the distal link is configured to rotate relativeto the proximal link about the first rotational axis.
 23. The armsupporting exoskeleton of claim 22, wherein an end of the tensile forcegenerator is coupled to the proximal link.
 24. The arm supportingexoskeleton of claim 23 further comprising an offset adjustment jointconfigured to adjust orientation of the proximal link relative to agravity line.
 25. The arm supporting exoskeleton of claim 23 furthercomprising a bracket coupling the tensile force generator to the distallink or the proximal link, wherein: an effective length of the tensileforce generator is a distance between a first distance and a seconddistance, the first distance is defined along the proximal link from thefirst rotational axis where the tensile force generator is coupled tothe proximal link, the second distance is defined along the distal linkfrom the first rotational axis where the tensile force generator iscoupled to the distal link, and location of the bracket adjusts theeffective length of the tensile force generator.
 26. The arm supportingexoskeleton of claim 22 further comprising a shoulder base coupled tothe proximal link, wherein the shoulder base is configured to be coupledto a trunk of the person and transfer at least a portion of a reactionforce from the torque to hips of the person.
 27. The arm supportingexoskeleton of claim 26, wherein: the proximal link, the distal link,the protrusion, and the tensile force generator are parts of an arm linkmechanism, the arm link mechanism further comprises at least onehorizontal rotation joint configured to rotate about a second rotationalaxis substantially orthogonal to the first rotational axis.
 28. The armsupporting exoskeleton of claim 27, further comprising a shoulderbracket configured to provide a quick connect and disconnect couplingbetween the shoulder base and the arm link mechanism.
 29. The armsupporting exoskeleton of claim 17, wherein: the tensile force generatorcomprises at least one line element and at least one spring element, theat least one spring element is configured to generate the torque, the atleast one line element is selected from the group consisting of a wirerope, a rope, a cable, a twine, a strap, a chain, or any combinationthereof, and the protrusion constrains the at least one line element.30. The arm supporting exoskeleton of claim 17, wherein: the tensileforce generator comprises a plurality of spring elements, and at leastone of the plurality of spring elements is configured to be activatedindividually or collectively.